Digital cameras and other digital imaging devices use arrays of millions of tiny photodetectors or pixels to record an image. For example, when a cameraman or camerawoman presses his or her camera's shutter button and exposure begins, each photodetector in the array is uncovered to detect the presence or absence of photons at the individual array locations. To end the exposure, the camera closes its shutter, and circuitry in the camera assesses how much light (e.g., how many photons) fell into each photodetector while the shutter was open. The relative quantity or intensity of photons that struck each photodetector are then stored according to a bit depth (0-255 for an 8-bit pixel). The digital values for all the pixels are then stored and are used to form a resultant image.
Conventional solid state image sensors are made up of an array of photodetectors which individually include PN junctions made of semiconductor material, for example, silicon disposed in a semiconductor substrate. Color filter arrays (CFAs) with separate color filters for red, blue, and green light are often arranged over photodetector arrays to differentiate between different colors of light. When an incident light ray has a large angle of incidence, the light can easily pass through one color filter into other neighboring color filters and/or other neighboring photodetectors underneath the color filters. Thus, a shield or re-direct element is inserted between photodetectors of different colors to reduce the crosstalk between photodetectors of different color filters, which otherwise will ultimately cause noise that distorts the resultant digital images.